I have a Fluid Designers sump and refugium as well. Been running it since August and I love it! Works incredibly well for nitrates and phosphates. I have 2 of these clipped on to the fuge http://m.homedepot.com/p/Philips-120W-Equivalent-Daylight
-5000K-PAR38-Dimmable-LED-Flood-Light-Bulb-425280/203553286
I run them 24/7, and while my fish aren't huge yet, I have a heavier stocked 75g, I throw probably 3/4 of a cube of frozen hikarari food in once a day, and I have no detectable nitrates or phosphates. Granted I have a big skimmer too..